This application relates generally to Bose-Einstein condensates. More specifically, this application relates to a multichamber Bose-Einstein-condensate vacuum system.
Ultracold-matter science has been a blossoming field of atomic physics since the realization of a Bose-Einstein condensate in 1995. This scientific breakthrough has also opened the way for possible technical applications that include atom interferometry such as might be used for ultrasensitive sensors, time and frequency standards, and quantum information processing. One approach for developing technology involving ultracold matter, and particularly ultracold atoms, is the atom chip. Such chips are described in, for example, J. Reichel, “Microchip traps and Bose-Einstein condensation,” Appl. Phys. B, 74, 469 (2002), the entire disclosure of which is incorporated herein by reference for all purposes. Such atom chips typically use currents in microfabricated wires to generate magnetic fields to trap and manipulate atoms. This chip approach allows for extremely tight confinement of the atoms and potential miniaturization of the apparatus, making the system compact and portable. But despite this, most atom-chip apparatus are of the same size scale as conventional ultracold atom systems, being of the order of one meter on one edge.
Current cold-atom and ion applications generally use an ultrahigh vacuum apparatus with optical access. The vacuum chamber of an atom chip typically provides an ultrahigh vacuum with a base pressure of less than 10−9 torr at the atom-chip surface. It also provides the atom chip with multiline electrical connections between the vacuum side of the microchip and the outside. Optical access may be provided through windows for laser cooling, with a typical system having 1 cm2 or more optical access available from several directions. A source of atoms or ions is also included.
Most conventional ultracold matter systems use multiple-chamber vacuum system: a high vapor-pressure region for the initial collection of cold atoms and an ultrahigh-vacuum region for evaporation and experiments. Chip-based systems have significantly relaxed vacuum requirements compared to their free-space counterparts, and many have used single vacuum chamber, modulating the pressure using light-induced atomic desorption. This approach may be problematic because it requires periodic reloading of the vacuum with the atom to be trapped, which in turn prevents continuous operation of the device. In addition, most ultracold matter vacuum systems use a series of pumps: typically a roughing pump, a turbo pump, one or more ion pumps, and one ore more titanium sublimation pumps. Such systems are large, costly, and poorly suited to applications for which small size, low weight, and low power consumption are emphasized.
There is accordingly a need in the art for improvements to systems for handling cold atoms.